Machine for curving strip material



Jan. 26, 1960 F. HONERKAMP ETAL MACHINE FOR cuavmc STRIP MATERIAL 5 Shae Filed Nov. 7, 1956 cs-Sheet y I, INVENTORS drich Honerkcunp,

I/ioivr Ollur idbe Jan. 26, 1960 F. HONERKAMP' ETAL 2,922,324

MACHINE FOR cuavmc. STRIP MATERIAL 5 Sheets-Sheet 2 Filed Nov. 7, 1956 INVENTORS Mdrzbhlibner factor 0.2;

Ramp, er,

WORM/77 Jan. 26, 1960 F. HONERKAMP ETAL 2,922,324

MACHINE FOR CURVING STRIP MATERIAL Filed Nov. 7, 1956 I 5 Sheets-Sheet 3 JNVENTORS T'im'e drich Honerkaznp,

Victor 0.Landbgr:g,

5 Sheets-Sheet 4 Jan. 26, 1960 Filed Nov. 7, 195a Jan. 26, 1960 F. HONERKAMP ETAL 2,922,324

MACHINE FOR CURVING STRIP MATERIAL Filed Nov. 7, 1956 *5 Sheets-Sheet 5 0 k fii Q Q 93 1 v "3 v INVENTORS f/ 6 rwedrichfl nermm United States Patent MACHINE FOR CURVING STRIP MATERIAL Friedrich Honerkamp and Victor 0. Lundberg, West Hartford, Conn., assignors to Anemostat Corporation of America, New York, N.Y., a corporation of Delaware Application November 7, 1956, Serial No. 620,848

3 Claims. (Cl. 80--'31.1)

This invention relates to a method of and a machine for curving or bending strip material, more particularly sheet or equivalent material, in the plane thereof, and is specially concerned with the production of flat rings, angle rings and the like such as are used extensively in heating, ventilating and various other arts, although it may be employed for producing circular or arcuate articles of various different types for a variety of other uses.

Heretofore, fiat rings usually have been die cut from sheet material and angle rings usually have been die pressed from sheet material, which has resulted in a great amount of waste of material. Moreover, die pressing angle rings from sheet material results in considerable stretching and distortion of the material and consequent imperfect rings. Accordingly, one special and important object of the present invention is to provide a simple, practical method, and a simple practical machine for carrying out the method, whereby fiat rings, angle rings and the like may rapidly and easily be produced substantially perfectly from strips of sheet or equivalent material practically without any waste of material and at exceptionally low cost.

The present method resides in pressure-reducing the thickness of a strip of material from one side edge thereof a progressively decreasing amount toward the opposite side edge thereof progressively along the length of the strip by rolling, harmnering or' in any other suitable manner. increasing amount fromits second mentioned side edge toward its first mentioned side edge with the result that the strip is curved or bent either into arcuate shape or full circular shape, depending upon the length of the strip and the amount of the thickness-reducing pressure that is applied thereto.

The present machine employs rolls for carrying out the method and in this connection another special and important object of the invention is to provide means whereby the placing of a strip in a starting position relative to the rolls causes the rolls to apply pressure to the strip and to maintain the pressure until the strip has been completely rolled. Also in this connection a further special and important object of the invention is to provide means whereby, upon completion of rolling of a strip, the rolls are separated and thereby are readied to have introduced between them another strip to be rolled.

The present machine additionally includes a form to be followed by a strip being curved and to preserve a predetermined curvature thereof and in this connection an additional special and important object of the invention is to provide means whereby the placing of a strip in a starting position relative to the rolls causes said form to be advanced to an operative position relative to the of a strip curving method, and in a strip curving machine embodying the novel features of construction, combination and arrangement of parts, as will hereinafter be more fully described, illustrated by way of example in the accompanying drawings and defined in the appended claims.

In the accompanying drawings, wherein like characters of reference denote corresponding parts in the different views:

Fig. 1 is a side elevation of a strip curving machine constructed in accordance with the invention.

Fig. 2 is a top plan view of the machine.

Fig. 3 is an enlarged longitudinal section through the roll mounting and driving portion of the machine.

Fig. 4 is an enlarged transverse section on the line 4-4 of Fig. 2.

Fig. 5 is an enlarged transverse section on the line 55 of Fig. 3.

Fig. 6 is an enlarged transverse section on the line 6-6 of Fig. 2.

Fig. 7 is a top plan view on an enlarged scale of the time switch and the strip hold-down device shown in Fig. 6.

Fig. 8 is an enlarged longitudinal section through a valve embodied in the machine; and

Fig. 9 is a diagrammatic perspective view illustrating the automatic control mechanism of the machine.

By reference to the drawings it will be observed that the present machine includes a suitable base, designated generally as 10, which appropriately may be of the construction shown comprising a pair of laterally spaced apart, longitudinally extending members 11, 11 rigidly connected together by suitable cross members 12 and supported on legs 13.

' Rigidly mounted on the members 11, 11 near the rear'end of the machine is a housing, designated generally as 14, which includes side walls 15, 15 between the Thereby the strip is elongated a progressively lower portions of which are suitably fixed a lower pair of bearings 16, 16 and between the upper portions of which is disposed a bearing box 17 in which are suitably fixed an upper pair of bearings 18, 18.

The lower pair of bearings 16, 16 may be fixed with respect to the housing 14 as, for example, by being bolted to the side walls 15, 15 of said housing, as indicated at 19. In any event, said bearings 16, 16 have journaled therein a shaft 20 which extends longitudinally of the machine and has fixed on its front end, forwardly of the housing 14, a roll 21.

rolls, and whereby, upon completion of rolling of a strip,

is better understood, the same consists in the novel steps Journaled in the upper pair of bearings 18, 18 is a shaft which also extends longitudinally of the machine and has fixed on its front end a roll 23 which overlies the roll Mating rearward extensions 24 and 25 of the side walls of the housing 14 and of the side walls of the bearing box 17, respectively, are pivotally connected together by horizontal pivot pins 26 and thereby said bearing box is pivotally supported by said housing for vertical swinging movement to provide for a small amount of vertical movement of the roll 23 relative to the roll 21.

On rear end portions of the shafts 20 and 22 are mounted spur gears 27 and 28, respectively, which mesh with each other, while on a suitable supporting structure 29 carried by the base 10 near the rear end of the machine is mounted a speed reductiongearing, designated generally as 30, and an electric motor 31 which operates through said gearing to drive a shaft 32 on which is mounted a sprocket Wheel 33 which is connected by a sprocket chain 34 to a sprocket wheel 35 mounted on the rear end of the shaft 20. Hence, when the motor 31 is operating, the shafts 20 and 23 and consequently the rolls 21 and 23 are driven in opposite directions.

Bolted or otherwise suitably fixed to the housing 14 and extending above the front end portion thereof is a block 36 to which a substantially horizontally disposed, longitudinally extending lever 37 is pivoted near its front end, as indicated at 38, for vertical swinging movement.

Forwardly of the pivot 38 of the lever 37 the block 36 has mounted therein for sliding movement a vertically disposed pin 39 which, at its upper end, is engaged by a front end portion of said lever 37 and which, at its lower end, carries a pad 40 which rests upon the top of the front end portion of the bearing box 17. Therefore, upward movement of the rear arm of the lever 37 and consequent downward movement of the front arm thereof results in the pin 39 and the pad 40 being forced downwardly against the bearing box 17 and thereby imparting downward swinging movement to said bearing box which, of course, results in downward movement of the roll 23. On the other hand, downward movement of the rear arm of the lever 37 and consequent upward movement of the front arm thereof releases the bearing box 17 for upward swinging movement by helical springs 41 interposed between the front bearing 16 and the front end portion of said bearing box which, of course, results in the roll 23 being raised relative to the roll 21. In this connection and as will, of course, be understood, the front arm of the lever 37 may be connected to the bearing box 17 so that the latter may be positively raised by said lever, in which event the springs 41 may be eliminated.

The front arm of the lever 37 is quite short and the rear arm of said lever is quite long so that a force applied upwardly upon the rear arm of said lever is multiplied many times to insure adequate pressure of the rolls 21, 23 upon a strip interposed between them.

Underlying the rear end of the lever 37 is a vertically disposed cylinder and piston power unit, the cylinder 42 of which is pivotally mounted at its lower end upon the base 10, as indicated at 42, and the piston 44 of which is connected by a rod 45 to the said rear end of said lever 37. Hence, by admitting air or other fluid under pressure to the lower end of said cylinder 42, the piston 44 is forced upwardly and imparts upward movement to the rear arm of the lever 37, while by admitting air or other fluid under pressure to the upper end of said cylinder, the piston 44 is forced downwardly and imparts downward movement to the rear arm of said lever 37.

Mounted upon the base as, for example, upon posts 46 rising from the members 11, 11, is a plate 47 upon which rests a block 48 which is retained upon said plate and is guided for sliding movement longitudinally of the machine by rails 49 secured upon the top of said plate along the sides thereof. The top of said block is disposed in, or substantially in, the plane of the top of the roll 21, while to either side of said block is a table 50 which consists of a pair of plates fastened upon the tops of the rails 49 and having their top surfaces disposed in the same plane as the top surface of said block 48.

The block 48 is disposed in front of the rolls 21, 23 and is provided with a vertical post 51 upon which may be rotatably mounted disks of various different diameters, one of which is illustrated and designated as 52. As shown, the post 51 is adjustable along a slot 53which extends longitudinally of the block 48, whereby any given disk 52 may be adjusted longitudinally of said block.

Suitably mounted on the base 10 at the front end of the machine is a cylinder and piston power unit, designated generally as 54, the cylinder 55 of which extends longitudinally of the machine and is fixed and the piston 56 of which is connected by a rod 57 to the block 48. Hence, by admitting air or other fluid under pressure to the front end of said cylinder, the block 48 is slid rearwardly, while by admitting air or other fluid under pressure to the rear end of said cylinder, the block 48 is slid forwardly.

Suitably mounted upon the base 10 of the machine is a bar 58 which extends laterally from said base approximately in line with the rolls 21, 23 and has suitably mounted thereon for adjustment therealong a two-way electric switch, designated generally as 59, which controls initiation of operation of the machine to roll and curve a strip of material as will later be explained.

Mounted upon the housing 14 is another two-way electric switch, designated generally as 60, which controls operation of the power unit 54 and which itself is controlled by movement of the lever 37 through an actuating finger 61 fixed to the long arm of said lever.

A strip a of material to be curved in accordance with the present method by the machine initially is placed in overlying relationship to the bar 58 at right angles to the axes of the rolls 21, 23 with its lead end portion resting upon the table 50 and with its lead end entered between said rolls 21, 23. In this connection, to guide the strip as it advances between the rolls 21, 23 and to hold it against lateral movement forwardly of the machine from between said rolls, the table 50 has mounted thereon a suitable guide member 62 with which the front side of the strip is engageable. Further in this connection, placing of a strip to be curved in its initial or starting position relative to the rolls 21, 23 is utilized to actuate another two-way electric switch, designated generally as '63, which controls operation of the machine in a manner soon to be explained.

The switch 63 is mounted in the present instance on the housing 14 in underlying relationship to the bar 58 and is of a well known type having a movable element which tends constantly to engage what will be termed a back contact and which, when shifted into engagement with what will be termed a front contact and then is released, will return to engagement with the back contact only after the elapse of a predetermined period of time which may be varied by an adjustment means with which the switch is provided. Since such switches are well known it is not considered necessary to illustrate the switch 63 in detail. Suflice it is to say that the same has pivoted thereto, intermediate its ends, as indicated at 64, a lever 65, one end portion or arm of which is disposed in a slot 66 in the aforesaid table 50 so as to underlie and be engaged by a strip to be curved which is disposed in its initial or starting position relative to the rolls 21, 23, and the other end portion or arm of which overlies a button 67 by which the movable element of the switch is moved from engagement with the back contact of the switch into engagement with the front contact thereof. Normally the first mentioned arm of the lever 65 is maintained elevated and the other arm thereof is maintained depressed, engaging the button 67 and holding the movable element of the switch engaged with the back contact, by any suitable resilient means such, for example, as a contractile helical spring 68 connecting the second mentioned arm of said lever with the casing of said switch.

When a strip a to be curved is placed in its starting position it rests upon and depresses the first mentioned arm and thereby elevates the second mentioned arm of the lever 65 and the button 67 thus is permitted to rise, which, in turn, permits the movable element of the switch to engage the front contact of the switch. On the other hand, in the absence of engagement of a strip with the first mentioned arm of the lever 65, the spring 68 acts to elevate said first mentioned arm of said lever and to depress the second mentioned arm thereof, thereby to depress the button 67 and to move the movable element of the switch to its normal position in engagement with the back contact of the switch.

In some instances the weight of a strip to be curved may be sufficient to depress the first mentioned arm of the lever 65. Preferably, however, a hold-down means for the strip is provided to insure that as long as the strip overlies the said first mentioned arm of said lever, said arm will be maintained depressed. Such a holddown means may be of any suitable form and is illustrated by way of example in the drawings as being mounted adjacent to the lever 65 on a supporting plate 69 fastened to the bar 58.

The plate 69 has fastened thereto and rising therefrom a housing 70 having spaced apart side walls between whlch is pivoted, intermediate its ends, a lever 71 one arm 72 of which is disposed to overlie a strip to be curved that is being fed between the rolls, 21, 23 and the other arm 73 of which has pivoted thereto, as indicated at 74, a floating actuating handle 75 which, at a point adjacent to the pivot 74, has pivoted thereto, as indicated at 76, one end of a link 77 the other end of which is pivoted to said housing 70 as indicated at 78.

The relationship between the lever 71, the handle 75 and the link 77 is such that by swinging the handle 75 upwardly the arm 72 of the lever 71 is swung upwardly to a position as illustrated by dotted lines in Fig. 6, to permit a strip to be curved readily to place in a starting position relative to the rolls 21, 23. The said relationship additionally is such that by swinging the handle 75 downwardly to a horizontal or substantially horizontal position, the lever 71 is swung downwardly to a similar position in which it is locked against upward swinging movement except by means of said handle 75.

The arm 72 of the lever 71 carries a contact element 79 which, when said lever is in a horizontal or substantially horizontal position, overlies and engages a strip advancing between the rolls 21, 23 and holds the strip against upward movement from a position in which it is holding the underlying first mentioned arm of the lever 65 depressed. The handle 75 is, of course. manually operable to swing the lever 71 between its inoperative and its operative positions.

A solenoid-operated valve, designated generally as 80, is employed to control admission of air or other fluid under pressure to the ends of the cylinder 42, and a similar valve, designated generally as 81, is employed to control admission of air or other fluid under pressure to the ends of the cylinder 55. Said valves may be mounted at any convenient positions on the machine, but preferably are located adjacent to the cylinders 42.and 55, respectively.

As illustrated in detail in Fig. 8 of the drawings, the valve 80 comprises a casing 82 having a longitudinal bore 83 in which is disposed a reciprocal spool-type valve 84 for controlling flow of fluid from a fluid inlet or supply conduit selectivelyto a pair of fluidoutlet conduits 86 and 87 and selectively from the latter conduits to the atmosphere through a pair of ports 88 and 89.

The fluid supply conduit 85 is connected to the bore 83 at a point preferably but not necessarily midway between the ends of said bore. In any event, the fluid outlet conduits 86, 87 are connected to said bore at opposite sides of said inlet conduit and the exhaust ports 88 and 89 are disposed outwardly of said conduits 86 and 87, respectively. a

The spool valve 84 isshiftable in one direction by a solenoid 90 carried by the casing 82 at one end thereof and is shiftable in the opposite direction by a solenoid 91 carried by said casing at the other end thereof. Moreover, said spool valve has a pair of reduced diameter portions 92 and 93 so spaced apart that when said valve is shifted by the solenoid 90, the inlet conduit 85 is placed in communication with the outlet conduit 87 and the outlet conduit 86 is placed in communication with the atmosphere through the port 88, while on the other hand, when said valve is shifted by the'solenoid 91, the inlet conduit 85 is placed in communication with the outlet conduit 86 and the outlet conduit 87 is placed in communication with the atmosphere through the port 89.

Since the valve 81 is, or may be, a duplicate of the valve 80, it is not illustrated in detail. Suflice it is to say that the same has connected therewith a fluid inlet conduit 94 and a pair of fluid outlet conduits 95 and 96 and that it is operable in the same manner as the valve 80 by means of a, pairof solenoids 97 and 98. In other Iwords, when the solenoid 97 is energized the inlet con duit 94 is placed in communication with the outlet conduit 95 and the outlet conduit 96 is vented to the atmosphere, and when the solenoid 98 is energized the inlet conduit 94 is placed in communication with the outletconduit 96 and the outlet conduit 95 is vented to the atmosphere.

The outlet conduits 86 and 87 of the valve are connected with the upper and the lower ends, respectively, of the cylinder 42, while the outlet conduits 95 and 96 of the valve 81 are connected with the rear and the front ends, respectively, of the cylinder 55. Air or other fluid under suitable pressure is supplied to the inlet conduits and 94 from any suitable source.

Referring now particularly to Fig. 9 of the drawings, it will be noted that a first current supply conductor 99 is connected to the movable elements 100, 101 and 102 of the switches 59, 60 and 63, respectively, and that a second current supply conductor 103 is connected to one terminal of each of the solenoids 90, 91, 97 and 98. It will further be noted that the other terminal of the solenoid is connected by a conductor 104 to the back contact'105 of the switch 63; that the other terminal of the solenoid 91 is connected by a conductor 106 with the front contact 107 of the switch 63; that the other terminal of the solenoid 97 is connected by a conductor 108 with the back contact 109 of the switch 60, and that the other terminal of the solenoid 98 is connected by a conductor 110 with the front contact 111 of the switch' 60.

Additionally it will be noted that the back contact 112 of the switch 59 is connected by a conductor 113 with the back contact 105 of the switch 63 and that the front contact 114 of the switch 59 is connected by a conductor 115 to the front contact 107 of the switch 63.

Normally the movable elements and 101 of the switches 59 and 63, respectively, are engaged with the back contacts 112 and of said switches as shown by full lines in Fig. 7. On the other hand, the movable element 102 of the switch 60 normally is engaged with the front contact 111 of said switch due to the roll 23 normally being elevated and maintaining the long arm of the lever 37 depressed. In other words, when the long arm of the lever 37 is depressed the finger 61 carried thereby engages and depresses a button 60 of the switch 60 and thereby maintains the movable element 102 of said switch engaged with the front contact 111 of said switch as shown by full lines in Fig. 7. Accordingly, when the conductors 99 and 103 are connected with a source of current, as by means of a switch 116, a circuit is closed through the solenoid 90 via the conductor 99, the movable element 101 of the switch 63, the back contact 105 of said switch, the conductor 104 and the conductor 103. At the same time another circuit is closed through said solenoid 90 via the conductor 99, the movable element 100 of the switch 59, the back contact 112 of said switch, the conductor 113, the back contact 105 of the switch 63, the conductor 104 and the conductor 103. Therefore, the valve 80 will be actuated to admit fluid under pressure through the conduit 86 to the upper end of the cylinder 42 to insure depression of the long arm of the lever 37 and elevation of the roll 23. Simultaneously a circuit will be closed through the solenoid 98 of the valve 81 via the conductor 99, the movable element 102 of the switch 60, the front contact 111 of said switch, the conductor and the conductor 103. Therefore, the valve 81 will be actuated to admit fluid under pressure through the conductor 95 to the rear end of the cylinder 55 with the result that the disk 52 will be shifted forwardly from the rolls 21, 23. In other words, connecting the conductors 99, 103 with a source of current insures opening of the rolls 21, 23 and retraction of the disk 52, thereby readying the machine to receive a strip a of material to be rolled or curved.

To initiate rolling of a strip a, the hold-down arm 71 is swung upwardly by manual actuation of the lever 75 and the strip is placed in a starting position in overlying relationship to the bar 58 with its front or lead end entered between the rolls 21, 23 and with its rear or trailing end disposed against a button 117 by which the movable element 100 of the switch 59 is shiftable from engagement with the back contact 112 to engagement with the front contact 114 of said switch. The hold-down arm 71 then is swung to its lower or operative position to insure that the strip will engage and depress the underlying arm 65 of the switch 63 and thus permit the movable element 101 of said switch to engage the front contact 107 of said switch. This, of course, will break the circuit through the solenoid 90 via said switch 63 and will close a circuit through the solenoid 91 via the conductor 99, the movable element 101 of the switch 63, the conductor 106 and the conductor 103. The circuit through the solenoid 90 will be maintained, however, through the switch 59.

The valves 80, 81 are of a well known commercial type embodying a construction such that, when either solenoid is energized and the other solenoid subsequently is energized, the spool valve 84 will not be moved from the position to which it was actuated by the first mentioned solenoid until the said first mentioned solenoid is deenergized. Accordingly, even though placing of a strip to be rolled in a starting position causes actuation of the switch 63 to close a circuit through the solenoid 91, the spool valve 84 of the valve 80 will remain in a position 'to admit air to the top of the cylinder 42 due to the circuit through the solenoid 90 being maintained via the switch 59.

During operation of the machine the rolls 21, 23 are driven continuously at a constant rate of speed by the motor 31. Now, with the strip a positioned as stated, in order to start actual rolling of the strip the same simply 'is given manually by the operator of the machine a slight eudwise outward movement suflicient to cause its outer end to engage the button 117 of the switch 59 and to actuate said-button to shift the movable element 100 of said switch from engagement with the back contact 112 into engagement with the front contact 114 as shown by 'dotted lines in Fig. 9. This will result in opening of the circuit through the solenoid 90. Thereupon, since only the solenoid 91 then will be energized, the spool valve 84 will be shifted to establish communication between the conduits 85 and 87 and to vent the upper end of the cylinder 42 through the conduit 86. This will result in upward movement of the piston 44 and in elevation of the rear end of the lever 37 with consequent downward :movement of the short front arm of said lever. Downward swinging movement thereby will be imparted to the bearing box 17 with the result that the roll 23 will be 'forced downwardly toward the roll 21 and the lead end of the strip a will be subjected to high pressure between said rolls. At the same time, the strip will begin to advance between said rolls due to the latter'being continuously driven.

Upon upward movement of the rear or long arm of the lever 37 the movable element 102 of the switch 60 was released to move from its full line position'in Fig. 9 to its dotted line position in said figure. This results in deenergization of the solenoid 90 and in energization of the solenoid 97 of the valve 81 with consequent actuation of said valve to vent the rear end of the cylinder 55 and to admit fluid under pressure to the front end thereof. Thereupon, the block 48 is shifted rearwardly and carries the form disk 52 rearwardly to a position to engage the forward side of the strip a and to prevent said strip from moving forwardly from between the rolls 21, 23.

If a flat ring or a flat element ofarcuate shape is to be formed by the machine, the strip a will, ofcourse,

'Asimplybe flat. -If,-on the other hand, -an=angle ring or an angle element of arcuate shape is to be formed bythe machine, the strip a will, of course, comprise, in cross section, two flanges disposed at right angles or in other desired angular relationship to each other. In this connection the drawings illustrate the strip a as being of angular shape in cross section and as having right angularly disposed horizontal and vertical flanges a and a, respectively. Only the horizontal flange a is entered between the rolls 21, 23, the vertical flange a" being disposed forwardly of said rolls and being engaged by the disk 52.

When the rolls 21, 23 are closed the relationship between their peripheral faces is such as to define between them, in the plane of the axes of the rolls, a space of wedge shape which diverges forwardly or outwardly relative to the rolls. This may be due to the roll 23 being tapered forwardly or outwardly, as shown, or alternatively and if desired, it may be due to a forward divergence of the axes of the rolls. In any event, due to the forward divergence of the space between the peripheries of the rolls, the latter will act upon the horizontal flange a of the strip a to pressure-reduce its thickness from its rear or inner side edge a progressively decreasing amount toward its front or outer side edge progressively along its length as it advances between the rolls. As a consequence, said flange a will be elongated a progressively increasing amount from its front or outer side edge toward its rear or inner side edge, which inherently results, of course, in curvature of said flange in its plane and, consequently in corresponding curvature of the vertical flange a".

As will be understood, the length of the strip a and the amount of pressure applied by the rolls 21, 23 are predetermined so that the strip may be curved into only arcuate shape or full circular shape as desired. As will also be understood, the disk 52 selected for use during any given strip curving operation of the machine will have a radius such that its peripheral curvature will correspond to the curvature imparted by the rolls 21, 23 to the strip being curved. Therefore as the strip emerges from between the rolls 21, 23, it will advance around the disk 52 and its curved form will be preserved by said disk.

When, during advance of the strip a, its outer or trailing end passes the underlying end of lever of the time switch 63, said lever will be released for actuation by the spring 68 to depress the button 67 of said switch 63. This will result, of course, in return movement of the movable element 101 of said switch 63 from engagement with the front contact 107 of said switch into engagement with the back contact 105 of said switch. However, this return movement of the movable element 101 will be delayed, due to the predetermined timing action of the switch 63, until the trailing end of the strip a has passed beyond the rolls 21, 23. Immediately or at any suitable time thereafter, however, the movable element 101 of the switch 63 will return to its normal position in engagement with the back contact 105 of the switch 63 and thereby the circuit through the solenoid 91 of the valve will be opened and a circuit will be established through the solenoid of said valve. This will result in actuation of said valve 80 to vent the lower end and to admit fluid under pressure to the upper end of the cylinder 42, whereupon the piston 44 will be moved downwardly to actuate the lever 37 to release pressure upon the bearing box 17. The springs 41 then will expand and elevate the front end of said bearing box 17 and thereby raise or open the roll 23 relative to the roll 21. At the same time, the movable element 102 of the switch 60 will be actuated by the lever 37 from engagement with the back contact 109 into engagement with the front contact 111 of said switch, which will result in opening of the circuit through the solenoid 97 and inclosing of a'circuit throughthe solenoid 98 of the 'valve 81. This, in turn, .willresult, of course, in actuation of said valve 81 to vent the outer or forward end and to admit fluid under pressure to the inner or rear end-of the-cylinder 55,-with the result that the block 48 will be shifted forwardly and will carry with it the form disk 52 and the strip a which has been curved therearound to a suitable position forwardly of the rolls 21, 23 for convenient removal of the curved strip a from said form disk. The parts of the machine now are in their original or normal relationships to each other adapting the machine to receive and curve another strip in the manner recounted.

After a strip has been curved by the machine into circular shape its ends may be united by welding or in any other suitable manner to provide a continuous ring.

As will be apparent, only a single attendant is required to operate the machine simply by placing strips a successively in a starting position relative to the rolls and by slightly shifting the strips outwardly to actuate the switch 59, all other operations of the machine being automatic. As will further be apparent, the strips a may be formed rapidly into arcuate or circular shape with tremendous savings in time, material and expense as compared with the common prior practices of die cutting or die stamping flat or angle rings or the like from sheets of material.

Obviously, the lower roll 21 is the equivalent of an anvil and the upper roll 23 is the equivalent of a hammer. Therefore, within the purview of the invention, the lower roll 21 may be replaced by an anvil and the upper roll 23 may be replaced by a suitable hammer.

From the foregoing description considered in connection with the accompanying drawings, it is believed that the present method and machine will be clearly understood and that their advantages will be appreciated. It is desired to point out, however, that both may be modified in various respects within the spirit and scope of the invention as defined in the appended claims.

'We claim:

1. A strip curving machine, comprising, a pair of rolls the peripheral faces of which are related to each other to define between them a wedge-shaped space, said rolls having their center axes disposed in substantially parallel planes, means for driving at least oneof said rolls to feed a strip between them, whereupon said strip is curved, a circular form disc about which the curved strip is wrapped in embracing relation thereto as it emerges from the rolls and to preserve a predetermined curvature of said strip, means mounting said disc for advance to and retraction from an operative position relative to said rolls so that the center axis of said disc intersects the center axes of said rolls, and means operable by placement of the strip in a starting position relative to said rolls to advance said disc to its operative position and operable by completion of advance of the strip between said rolls to retract said disc from its operative position for convenient removal of the curved strip therefrom.

v 2. A strip curving machine, comprising a pair of rolls the peripheral faces of which are related to eachv other to define between them a wedge-shaped space, said rolls having their center axes disposed in substantially parallel planes, means for driving at least one of said rolls to feed a strip between them, a circular form disc about which the curved strip is wrapped in embracing relation thereto to preserve a predetermined curvature thereof as the strip emerges from the rolls, means mounting said disc for advance to and retraction from an operative position relative to said rolls so that the center axis of said disc intersects the center aXes of said rolls, a support beneath the disc and cooperating therewith to maintain the curved strip co-planar with said disc, means operable by placement of the strip in a starting position relative to said rolls to initiate operation of said power means, means operable by initial operation of said power means to project said disc to an operative position relative to said rolls, means operable responsive to completion of advance of the strip between the rolls to move said bodily movable roll away from the other roll for introduction between them of another strip to be rolled, and means operable responsive to operation of said last mentioned means to retract said disc from its operative position to a position for convenient removal of the curved strip therefrom.

3. A strip curving machine according to claim 2, wherein said support comprises a pair of co-planar tables disposed in spaced relationship and underlying diametrically opposite segments of said disc.

References Cited in the file of this patent UNITED STATES PATENTS 908,859 Gustaven Jan. 5, 1909 1,158,294 Robinson Oct. 26, 1915 1,399,951 Forsyth Dec. 13, 1921 1,698,149 Bailey Jan. 8, 1929 1,943,407 Yoder Jan. 16, 1934 2,776,585 Kendall Ian. 8, 1957 FOREIGN PATENTS 26,404- Switzerland July 4, 1902 418,609 France Oct. 3, 1910 307,706 Great Britain Dec. 19, 1929 

